Cradle operating cylinder



Aug. 14, 1945. D. WERTMAN ETAL CRADLE QPERATING CYLINDER Filed Nov. 30, 1943 4 Sheets-Sheet `1 E; .mung

Aug.14, 1945. WERTMAN ETAL 2,382,457

CRADLE OPERATING CYLINDER INVENToRs DAVID WERTNV BY FRN?Z%CK 77ATTOR EMA ug i4 1945 D. WERTMAN' Erm. 25382457 i CRADLE OPERATING CYLINDER Filed Nov. so. 1945 4 shets-sneet 4 v f I l I y s i@ I' ,y Z g 'Illl A ,lew'aa/S aviduffertmaw ai, Fal Wa'lia/ 12g LW Patented Aug. 14, 1945 CRADLE OPERATING CYLINDER David Wertman and Frank Warlick, Washington, D. C.

'Appueatien November 8o,` 1948, serial No. 512,386 e (Granted under the aet ef Maren 3,1883, as

amended April 30, 1928; 3700. G.757)

Claims.

This invention relates to hydraulic means for operating the cradlerat a gun emplacement for handling large size ammunition between the hoist and the breachv of the gun. Normally the ammunition is. hauled up vertically by hoistingv means and is placed in the cradle in substantially upright position 'while the cradle is retracted. In order to turn the ammunition into a more or less horizontal position for feeding into the gun barrel, the cradle in which the ammunition is placed has .to turn through about 90, while the cradle is simultaneously extended by a spanning trayso as to deliver the ammunition horizontally up to thev mouth of the gun barrel.

It is the function-of the present invention to operate the cradle by turning it from retracted or upright position to extended or lowered position and vice versa with proper speeds and accelerations, so as to reduce. shock due to inertia and gravity` forces of the massivecradle structure itself as well as the heavy Apieces of ammunition that it is loaded with during the feeding portions of its operation.

Fig. 1 showsthe general assembly of the cradle operating cylinder applied to a cradle of the four-link type,

Figs. 2 and 3 are sectional views taken at 2-2 and 3 3 respectively of Fig.=1,

Fig. 4 is a cross sectional view taken at 4-4 of Fig, 1, e,

Fig. 5 is a cross sectional View taken at 5--5 ofllig.4,andv v Y Figs. 6 and 7 are diagrammatic views of the hydraulic system used in the control of the cradle operating cylinder, Fig. 6 showing the controls in the cradle extending position, while the other gure shows them in cradle retracting position.

and Ill-Ill respectively in Fig. l.

The particular type and design of cradle shown in Fig. 1 is adapted to move the spanning tray 2 in a denite path in a restricted space as the main portion of the cradle is turned on its trunnions 9 from one position to the other. This is done by means of a four-link leverage system, the portion of the stationary base structure I0 between pivots 9 and I formingthe stationary link, and the members I,. 2 4and 6 providing the three movable links extending between the pivots 9 and 4, 4 and'li and?! and 5 respectively. The extended position of the cradle is shown in full lines, the dot and dash lines indicating it in the retracted position,

. AThe cradle operating-.cylinder I3 is hinged at4 I2 to the base support Il byv means of bearing portion pivotally mounted on the pin44. End

plate 49 is fastened to the base support and holdsthe pin 44 in place in the base'support. End

. portion 4l is mounted at one side of the base support vrII to form a bearing for one end 29 oi' the nscillatable fitting 55, the other end of which bears in the side of the base support. Endportion 43 is mounted at the side of plate 49l toperform a similar function for the oscillatable littihg 3U, whose other bearing is formed in the plate 49. f l n These ttings provide the hydraulic connections between the. passages in the basesupport and the conduits leading to the cylinder valves. The loperating piston 43 in the cylinder chamber 3l has a. rod i4 extending through the other end of thel cylinder for pivotal connection at 46 to the main portion of the cradle at 8. V-The cradle is shown in its extended position in Fig. 1 in full lines, and its retracted position is indicated by dot and dash lines. The hydraulic system-for the operating cylinderis shown diagrammatical- 1y in Figs. 6 and 7. A hydraulic pump 33 is op erated vby motor 32 and is supplied by iluid fromv the tank 34 throughconduit 35. This pump delivers the liuid under pressure through conduit 36 to the control valve `56 which is'foperatedby control lever 40.to directthe pressure fluid into either of the conduits 2l or 28fwhile at the same time relieving `the other of these conduits to'the return conduit 38 which leads back to the tank 34. A pressure relief valve 3l is used between thedelivery conduit 36 and return conduit 38. Conduits 2l and 28 are connected to the rigid base support as shown in Fig. 3. These conduitsl are connected through the oscillatable iittings and 30 tothe conduits l5 and I6 respectively, which are rigid with the cylinder structure. Conduit I5 leads tothe head end of the cylinder and supplies the fluid through check'valve 20 and the adjustable orice at I9 to the head end of the chamber 3| until 'the piston 43 clears the port 51. Then the fluid is supplied without restriction to chamber `3l until the control lever 4l) is released or until the piston reaches the other end of the chamber. When lever 40 is released, spring -42 moves the control valve into neutral position, in which it permits the ow of iuid directly from the pump delivery `conduit to the return conduit-38.` While the piston is moving away from the headr end of the cylinder the iluid at the other end is releasedjthrou'gh the check valve 24 and the'restriction at 23 to' the return conduit 38 via the conduits I6 and 28 and the control valve passages. 1 When the control lever 40 is shifted to th position shown in Fig. 7, theA fluid under pressure is directed to the conduit 28, through conduit I6 and check valve 25 and the restriction at 26 to the rear end of the cylinder chamber until the port 58 is cleared by the vpiston and then the fluid under pressure flows into the cylinder chamber without restriction through they port 58 moving the piston to the other end of the cylinder, from which the fluid is released through check valve 2l and the restriction at 22 to the conduit I and from there to the return conduit 38 via the conduit 2l and the passages.

in the control valve. By proper adjustment of" the restrictions at I9, 22, 23 and 26, the desiredv accelerations and speeds of operation of the piston 43 may be obtained in moving the cradle at the desired speeds under the prevailing loads.y The novel arrangement consisting of ythe two check valves and the two adjustable V.orifices at each end ofthe cylinderis provided in orderto `take care of the unbalanced and continuouslyvarying loads imposed upon the cradle operating cylinder during the movement of the cradle. The direction and magnitude of the-loads imposed upon the cradleoperating .cylinder during the movement of the cradle may be consideredr asdivided into. three phases: y

l. Starting with the cradle in its.l fully retracted position and moving the cradle towards its.

trationsV of Figsfi and '1, when the control valve is shifted tothe position. showninlig.V 6, fluid under pressure from .the pump.- willbe ported through the control valve tothe. head ena of the operating, cylinder, and the. piston rod end of the cylindery will be` vented to the. tank. Atthe head endV of the hydraulic cylinder the oil will be blocked by check valve 2I .but will be ported. through the check valve 28 then through the orifice I9 tothe left side of the piston.` .The force onthe piston willcause the piston to moveA to` the right, thereby rotating the cradle. The discharge from the piston rod side of the operating cylinder will be ported through the upper check valve 2,4 and through` the adjustable ori.

ce 23 to the tank. The pressure drop across.

each orifice will limit the force applied to theV piston rod and thus control the acceleration of the cradle.

During the flrst'part of the piston movement the flow of oil willpass into the two orifices I9 and 23. However, as soon as the piston uncoversA a port 51 in the cylinder the oil will flow directly into the cylinder without passing through the orifice `IIl atthe upper-left side. By'proper adjustment of the orifice I!)4 at theA upper left side of the operating cylinder,y the desired acceleration of the cradle may be obtained.

During the last part of the cradle movement, the unbalanced weight of the moving system tends to move the cradle to its fully extended `is follows; Referring tothe .diagrammatic v.illusythereon or therefor.

position. However, the maximum speed of the piston will be limited by the pressure drop across the orice 23 at the upper right side of the operating cylinder. The final deceleration and stopping of the cradle is accomplished by an external buffer 50. Thus, it can be seen that one orifice I9 controls the 'acceleration of the cradle and the second orifice 23 controls the maximum speed of the cradle, thus reducing and limiting the shock on the moving system. The operation of rotating the cradle from its extended to its retracted position is shown in the diagram of Fig. '7. The action is similar to that described above, except that the second pair of check valves 25 and 2| and adjustable orifices 26 and 22 shown at the bottom of the cylinder will be used instead of-the upper pair of valves 20 and 24 and orifices I9. and 23.

The sectional view of the swivel joint in Fig. 3 'shows the two main conduits 21 and 28 from the control valve and the two main conduits I5 and vI6 leading to the oscillatable cradle operating cylinder. A third conduit I8 of a smaller dlameter is also shown with two connections to each end of the operating cylinder. The purpose of this conduit isto drainto the tank the oil leakage past the piston ro'd packing and all the adjustable orifice rods. Tank connections 5I, 52 and 53 are also shown for the oil seepage past the swivel jointsof the fittings 55 and 30.

The connections of the conduit I8 to the several points of oil leakage may be more clearly seen in Figs. 8 .to 10,. wherein 53' is the interconnecting conduit in the wall atthe head end. of the cylinder between the two orifice rods at that end. A similar conduit in the wall at the piston rod end of the cylinder may be seen interconnected with the leakage chamber from the packing around the piston rod I4.

This. invention is not limited tothe .preferred forms of the details of the device herein clisclosed, but may be varied within the scope of the appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposes without the payment of.any. royalties `What is claimedis:

1. A cradle operating mechanism comprising a base support, a cylinder pivotally connected at one end to said support and having a hydraulically actuated piston therein with a piston rod extending through the other end and pivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, and a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves to said port, and to the extreme end of the cylinder by way of one of the restrictions, and for relieving fluid from said end by way of the other check valve and the vother restriction.

2. A cradle operating mechanism comprising a base support, a cylinder pivotally connected at one end to said support and having a hydraulically actuated piston therein with a pistonfrod extending through the other end and pivoted to the cradle, a port inthe cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder c onnected for supplying fluid throughone of the check valves to said port, and to the extreme.

end of the cylinder by way of` one ofthe restrictions, and for relieving fluid from said end by way of the other check valve and the other restriction, and a control valve for selectively admitting fluid under pressure ltoeither one of said fluid supply and relief conduits while relieving the other.

3. A cradle operating mechanism comprising a base support, acylinder pivotally connected at one end to said'support and having a hydraulically actuated piston therein with a pistonl rod extending through the other end and pivoted to the cradle, .a port in thel cylinder wall'near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves to said port, and to the extreme end of the cylinder by way of one of the restrictions, and for relieving fluid from said end by way of the other check valve and the other restriction, and means for adjusting the size of each of the restrictions to regulate the speed of operation of the piston.

4. A cradle operating mechanism comprising a base support, a cylinder pivotally connected at one end to said sup-port and having a hydraulically actuated piston therein with a piston rod extending through the other end and pivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves to said port, and to the extreme end of the cylinder by Way of one of the restrictions, and for relieving fluid from said end by way of the other check valve and the other restriction, and swivelled fittings on the axis of the cylinder pivot in the base support, connected to the fluid supply and relief conduits for turning with the cylinder, and through the swivelled joints to passages n the base structure having fittings for connection to stationary portions of the fluid supply and relief conduits.

5. A cradle operating mechanism comprising a base support, a cylinder pivotally connected at one end to said support and having a hydraulically actuated piston therein with a piston rod extending through the other end and 'pivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves to said port and to the extreme end of the cylinder by way of one of the restrictions and for relieving fluid from said end by way 1 of the other check valve and the other restriction,

and swivelled fittings on the axis of the cylinder pivot in the base support connected tothe fluid supply and relief conduits for turning with the cylinder, and through the swivelled joints to passages in the base structure having fittings for connection to stationary portions of the fluid supply and relief conduits.

6. A cradle operating mechanism comprising a base support, a cylinder pivotally connected at one end to said support and having a hydraulically actuated piston therein with a piston rod extendingthrough the other end andpivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston-when at thev corresponding end, two checkyalvesand two restrictions at each endsof the cylinder,.a fluid supply and relief conduitfor each end .of the cylinder connected for supplyingv fluidthrough one of the check valves to said port and to the extreme end of the cylinder by way of oneof the. restrictions, for relieving fluid from said end byy way of the other check valve and the other restriction, and swivelled fittings on the axis, of the cylinder pivot in the base support connectedto the fluid supply and relief conduits for turning vwith the cylinder and through the swivelled joints to passages in the base structure having fittings for connection to stationary portions of the fluid supply and relief conduits and a control valve for selectively admitting fluid under pressure to either one of Said fluid supply and relief conduits while relieving the other.

7. A cradle operating mechanism comprising a base support, a cylinder pivo'tally connected at one end to said support and having a hydraulically actuated piston vtherein with a piston rod extending through the other end and pivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves'to said port and to the extreme end of the cylinder by way of one 0f the restrictions, and for relieving fluid from said end by way of the other check valve and the other restriction, swivelled fittings on the axisof the cylinder pivot in the base support connected to the fluid supply and relief conduits for turning with the cylinder, and through the swivelled joints to passages in the base structure having fittings for connection to stationary portions of the fluid supply and relief conduits, and means for adjusting the size ofeach of the restrictions to regulate the speed of operation of the piston.

8. A cradle operating mechanism comprising a base support, acylinder pivotally connected at one end to said support and having a hydraulically actuated piston therein with a piston rod extending through the other end and pivoted to the cradle, a port in the cylinder wall near each end of the cylinder closed by the piston when at the corresponding end, two check valves and two restrictions at each end of the cylinder, a fluid supply and relief conduit for each end of the cylinder connected for supplying fluid through one of the check valves to said port and to the extreme end of the cylinder by way of one of the restrictions, and for relieving fluid from said end by way of the other check valve and the other restriction, and swivelled fittings on the axis of the cylinder pivot in the base support connected to the fluid supply and relief conduits for turning with the cylinder, and through the swivelled joints to passages in the base structure having fittings for connection to stationary portions of the fluid supply and relief conduits, a, control valve for selectively admitting fluid under pressure to either one of said fluid supply and relief conduits while relieving the other, and means for adjusting the size of each of the restrictions to regulate the speed of operation of the piston.

9. Hydraulic means for reciprocating a piston in either direction for producing a desired cycle of varying forces during the piston stroke, a cylinder for said piston, a, source of fluid under constant pressure, a supplyandfrelief conduitrfor each end of the cylinder,4 a pair of valves anda pair 'of adjustable orices for each end of the cylinder, a connection from each conduit to the extreme end of the-cylinder through one of the pair of checkvalves and one ofthe pair of adjustable orifices, another connection from said end to said conduit throughthe other-of the check valves and the other of .the adjustable orices, a port near the end ofthe cylinder closed fby the piston when at the extreme end of `the cylinder and connected between said first check valve and said first orifice.

10. Hydraulic means for reciprocating a piston in either direction for producing a desired cycle of varying forces duringthe piston stroke, a cylinder for said piston, a. source of fluid under constant pressure, a. supply and relief conduit for each end of the cylinder, -a pair of valves and a pair of adjustable orices for eaach end of the cylinder, a connection from each conduit to the extreme enci'of the cylinder through one of the -pair of check valves and one of the pair of adjustable milices, another connection from said end to said conduit through the other of the check Valves and the other of the adjustable orices, a port near the end of the cylinder closed bythe piston when at the extreme end of the cylinder and ,connected between said first check valve and said rst orice, and! means for adjusting the size of each of said orifices.

i DAVID WERTMAN. FRANK WARLICK. 

